xref: /openbmc/linux/arch/x86/Makefile (revision a17922de) 
1# SPDX-License-Identifier: GPL-2.0
2# Unified Makefile for i386 and x86_64
3
4# select defconfig based on actual architecture
5ifeq ($(ARCH),x86)
6  ifeq ($(shell uname -m),x86_64)
7        KBUILD_DEFCONFIG := x86_64_defconfig
8  else
9        KBUILD_DEFCONFIG := i386_defconfig
10  endif
11else
12        KBUILD_DEFCONFIG := $(ARCH)_defconfig
13endif
14
15# For gcc stack alignment is specified with -mpreferred-stack-boundary,
16# clang has the option -mstack-alignment for that purpose.
17ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
18      cc_stack_align4 := -mpreferred-stack-boundary=2
19      cc_stack_align8 := -mpreferred-stack-boundary=3
20else ifneq ($(call cc-option, -mstack-alignment=16),)
21      cc_stack_align4 := -mstack-alignment=4
22      cc_stack_align8 := -mstack-alignment=8
23endif
24
25# How to compile the 16-bit code.  Note we always compile for -march=i386;
26# that way we can complain to the user if the CPU is insufficient.
27#
28# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
29# older versions of GCC, include an *assembly* header to make sure that
30# gcc doesn't play any games behind our back.
31CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
32M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
33
34REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \
35		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
36		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
37		   -mno-mmx -mno-sse
38
39REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
40REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
41REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
42export REALMODE_CFLAGS
43
44# BITS is used as extension for files which are available in a 32 bit
45# and a 64 bit version to simplify shared Makefiles.
46# e.g.: obj-y += foo_$(BITS).o
47export BITS
48
49ifdef CONFIG_X86_NEED_RELOCS
50        LDFLAGS_vmlinux := --emit-relocs
51endif
52
53#
54# Prevent GCC from generating any FP code by mistake.
55#
56# This must happen before we try the -mpreferred-stack-boundary, see:
57#
58#    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
59#
60KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
61KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
62
63ifeq ($(CONFIG_X86_32),y)
64        BITS := 32
65        UTS_MACHINE := i386
66        CHECKFLAGS += -D__i386__
67
68        biarch := $(call cc-option,-m32)
69        KBUILD_AFLAGS += $(biarch)
70        KBUILD_CFLAGS += $(biarch)
71
72        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
73
74        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
75        # with nonstandard options
76        KBUILD_CFLAGS += -fno-pic
77
78        # Align the stack to the register width instead of using the default
79        # alignment of 16 bytes. This reduces stack usage and the number of
80        # alignment instructions.
81        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))
82
83        # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
84        # a lot more stack due to the lack of sharing of stacklots:
85        KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \
86				$(call cc-option,-fno-unit-at-a-time))
87
88        # CPU-specific tuning. Anything which can be shared with UML should go here.
89        include arch/x86/Makefile_32.cpu
90        KBUILD_CFLAGS += $(cflags-y)
91
92        # temporary until string.h is fixed
93        KBUILD_CFLAGS += -ffreestanding
94else
95        BITS := 64
96        UTS_MACHINE := x86_64
97        CHECKFLAGS += -D__x86_64__
98
99        biarch := -m64
100        KBUILD_AFLAGS += -m64
101        KBUILD_CFLAGS += -m64
102
103        # Align jump targets to 1 byte, not the default 16 bytes:
104        KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
105
106        # Pack loops tightly as well:
107        KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
108
109        # Don't autogenerate traditional x87 instructions
110        KBUILD_CFLAGS += $(call cc-option,-mno-80387)
111        KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
112
113        # By default gcc and clang use a stack alignment of 16 bytes for x86.
114        # However the standard kernel entry on x86-64 leaves the stack on an
115        # 8-byte boundary. If the compiler isn't informed about the actual
116        # alignment it will generate extra alignment instructions for the
117        # default alignment which keep the stack *mis*aligned.
118        # Furthermore an alignment to the register width reduces stack usage
119        # and the number of alignment instructions.
120        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
121
122	# Use -mskip-rax-setup if supported.
123	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
124
125        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
126        cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
127        cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
128
129        cflags-$(CONFIG_MCORE2) += \
130                $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
131	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
132		$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
133        cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
134        KBUILD_CFLAGS += $(cflags-y)
135
136        KBUILD_CFLAGS += -mno-red-zone
137        KBUILD_CFLAGS += -mcmodel=kernel
138
139        # -funit-at-a-time shrinks the kernel .text considerably
140        # unfortunately it makes reading oopses harder.
141        KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
142endif
143
144ifdef CONFIG_X86_X32
145	x32_ld_ok := $(call try-run,\
146			/bin/echo -e '1: .quad 1b' | \
147			$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
148			$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
149			$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
150        ifeq ($(x32_ld_ok),y)
151                CONFIG_X86_X32_ABI := y
152                KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
153                KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
154        else
155                $(warning CONFIG_X86_X32 enabled but no binutils support)
156        endif
157endif
158export CONFIG_X86_X32_ABI
159
160#
161# If the function graph tracer is used with mcount instead of fentry,
162# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
163# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
164#
165ifdef CONFIG_FUNCTION_GRAPH_TRACER
166  ifndef CONFIG_HAVE_FENTRY
167	ACCUMULATE_OUTGOING_ARGS := 1
168  else
169    ifeq ($(call cc-option-yn, -mfentry), n)
170	ACCUMULATE_OUTGOING_ARGS := 1
171
172	# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
173	# If '-Os' is enabled, disable it and print a warning.
174        ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
175          undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
176          $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
177        endif
178
179    endif
180  endif
181endif
182
183ifndef CC_HAVE_ASM_GOTO
184  $(error Compiler lacks asm-goto support.)
185endif
186
187#
188# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
189# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226).  There's no way
190# to test for this bug at compile-time because the test case needs to execute,
191# which is a no-go for cross compilers.  So check the GCC version instead.
192#
193ifdef CONFIG_JUMP_LABEL
194  ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1)
195	ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1)
196  endif
197endif
198
199ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
200	# This compiler flag is not supported by Clang:
201	KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
202endif
203
204# Stackpointer is addressed different for 32 bit and 64 bit x86
205sp-$(CONFIG_X86_32) := esp
206sp-$(CONFIG_X86_64) := rsp
207
208# do binutils support CFI?
209cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
210# is .cfi_signal_frame supported too?
211cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
212cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
213
214# does binutils support specific instructions?
215asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
216asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
217asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
218avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
219avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
220avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
221sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
222sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
223
224KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
225KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
226
227LDFLAGS := -m elf_$(UTS_MACHINE)
228
229#
230# The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
231# the linker to force 2MB page size regardless of the default page size used
232# by the linker.
233#
234ifdef CONFIG_X86_64
235LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
236endif
237
238# Speed up the build
239KBUILD_CFLAGS += -pipe
240# Workaround for a gcc prelease that unfortunately was shipped in a suse release
241KBUILD_CFLAGS += -Wno-sign-compare
242#
243KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
244
245# Avoid indirect branches in kernel to deal with Spectre
246ifdef CONFIG_RETPOLINE
247ifneq ($(RETPOLINE_CFLAGS),)
248  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE
249endif
250endif
251
252archscripts: scripts_basic
253	$(Q)$(MAKE) $(build)=arch/x86/tools relocs
254
255###
256# Syscall table generation
257
258archheaders:
259	$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
260
261###
262# Kernel objects
263
264head-y := arch/x86/kernel/head_$(BITS).o
265head-y += arch/x86/kernel/head$(BITS).o
266head-y += arch/x86/kernel/ebda.o
267head-y += arch/x86/kernel/platform-quirks.o
268
269libs-y  += arch/x86/lib/
270
271# See arch/x86/Kbuild for content of core part of the kernel
272core-y += arch/x86/
273
274# drivers-y are linked after core-y
275drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
276drivers-$(CONFIG_PCI)            += arch/x86/pci/
277
278# must be linked after kernel/
279drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
280
281# suspend and hibernation support
282drivers-$(CONFIG_PM) += arch/x86/power/
283
284drivers-$(CONFIG_FB) += arch/x86/video/
285
286####
287# boot loader support. Several targets are kept for legacy purposes
288
289boot := arch/x86/boot
290
291BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
292
293PHONY += bzImage $(BOOT_TARGETS)
294
295# Default kernel to build
296all: bzImage
297
298# KBUILD_IMAGE specify target image being built
299KBUILD_IMAGE := $(boot)/bzImage
300
301bzImage: vmlinux
302ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
303	$(Q)$(MAKE) $(build)=arch/x86/tools posttest
304endif
305	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
306	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
307	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
308
309$(BOOT_TARGETS): vmlinux
310	$(Q)$(MAKE) $(build)=$(boot) $@
311
312PHONY += install
313install:
314	$(Q)$(MAKE) $(build)=$(boot) $@
315
316PHONY += vdso_install
317vdso_install:
318	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
319
320archclean:
321	$(Q)rm -rf $(objtree)/arch/i386
322	$(Q)rm -rf $(objtree)/arch/x86_64
323	$(Q)$(MAKE) $(clean)=$(boot)
324	$(Q)$(MAKE) $(clean)=arch/x86/tools
325
326define archhelp
327  echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
328  echo  '  install      - Install kernel using'
329  echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
330  echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
331  echo  '                  install to $$(INSTALL_PATH) and run lilo'
332  echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
333  echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
334  echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
335  echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
336  echo  '                  bzdisk/fdimage*/isoimage also accept:'
337  echo  '                  FDARGS="..."  arguments for the booted kernel'
338  echo  '                  FDINITRD=file initrd for the booted kernel'
339endef
340